In many present day military applications of guided missiles, the space requirements for a missile, due to wingspan, become an imposing factor. For example, the Penguin missile is a surface-to-surface weapon currently in the possession of a number of national navies. The missile is stored and launched from a canister approximately 43 inches .times.43 inches due to the relatively large wingspan of 1.49 meters. As will be appreciated, when storing a number of these missiles in canisters, the pressure of storage space becomes a primary concern. This is particularly the case when missiles of this sort are adapted for use by aircraft such as helicopters. If a relatively large missile with the corresponding necessarily large wingspan is to be employed, it has been recognized that a folding wing configuration must be designed to provide clearance with the ground plane and to provide a reasonable envelope when carried on an aircraft such as a helicopter.
If the folding wing configuration is to be employed, the fold mechanism must be enclosed within the wing contour and the wing deployment mechanism must be relatively lightweight and secure so that the wings will remain in a deployed position when a missile with the folding wing contour encounters air resistance and vibration after deployment.
The prior art discloses foldable wing structures for aircraft and missiles.
U.S. Pat. No. 2,719,682 to Handel discloses a foldable aircraft wing wherein lock pin linkages engage detents when the wing is fully deployed. The basic disadvantage of this reference is the reliance upon precise alignment of the lock pins with the corresponding detents to achieve a secure wing position. Oftentimes this is impossible to achieve after a missile becomes airborne and encounters vibration, turbulence and wind resistance. As a result, a deployed missile would quickly become unstable.
U.S. Pat. No. 2,876,677 to Clark, et al., discloses a missile with a folding wing structure which becomes locked into place upon deployment by a hook mechanism. Such a mechanism is unreliable when considering the wide variety of environmental conditions encountered by the wings during deployment.
U.S. Pat. No. 4,410,151 to Hoppner, et al., discloses a missile having folded wings which are hinged to spring mechanisms which force the wings to extend into a deployed position. Latches are utilized to lock the deployed wings into position. This patent suffers from the same problems as mentioned in connection with the Handel patent.